As is known, within an elevator compartment a car is arranged that is vertically slidable. Such a car has one or more passages or openings with which a door is associated.
In this context, reference is made to sliding car doors, in particular equipped with lower sliding blocks that slide within a groove or hollow afforded in the door sill. The guide for the car door panels through a grooved sill is known for car doors with one or more centrally or telescopically opening door panels, with linear or circular sills.
The presence of the sliding block in the door panels guarantees precise opening and closing, preventing the door panels themselves getting warped or broken.
One of the drawbacks of this solution is represented by the fact that the grooved sill gets filled with dirt and waste which, often being difficult to remove, may even hinder the sliding of the door panels.
When the car stops at a floor of the building, its sill is aligned with the sill of the relative floor door, arranging itself substantially at the same horizontal level as the latter.
As is known, between the outside of the car and the wall with which the floor doors are associated, there is an opening, i.e. an empty tolerance space in order to prevent the car interfering with the wall during its vertical motion, which would cause interference or collisions as well as noise in the system.
The presence of the opening between the car and the wall translates into a distance, for example 25-30 mm between the car sill and the floor sill. Therefore, there is a gap of a substantial size between the two sills, responsible for tripping, problems entering with prams or walking frames that have wheels, undesired falling of small items (e.g. keys), etc.
Since the opening between the car and the wall cannot be reduced below a minimum value—without compromising the quality of the car's travel and the wear on it—various manufacturers have tried to limit the size of the gap between the sills only during the car opening phase.
Document CN101948070 illustrates a centrally opening car door wherein an additional metal profile, equipped with an arched groove, is installed directly on the sill. Each door panel is provided at the bottom with a pin sliding in the arched groove so that, during the opening of the door, the sliding of such pin makes the additional profile advance until the gap is covered. Vice versa, when the door is closed the additional profile returns into the sill so as not to compromise the vertical motion of the car.
The concept of an “auxiliary sill” that is extractable/retractable with respect to the main sill of the car door is also proposed in documents CN102992151, JP2007320735 and WO2005/035421. Such documents show various auxiliary sill movement mechanisms, such as rollers, helical wheels, cams, etc. in some cases even very complex.
Furthermore, the extracted auxiliary sill is temporarily anchored to the floor sill to guarantee its stability.
Finally, the auxiliary sill is associated with a grooved sill for the sliding of the door, therefore the problem of dirt accumulating remains. Furthermore, these solutions are also affected by noise and vibrations.
A commercial solution proposed by the Applicant envisages during the opening of the car door the auxiliary sill being located in the centre of the gap so as to substantially split it into two smaller gaps.
In this context, the technical task at the basis of the present invention is proposing an elevator door and a method for opening an elevator door having two sliding door panels which overcome the problems of the prior art cited above.